It is estimated that as many as 15,000,000 individuals in the United States suffer from stomach acid reflux into the lower esophageal region, commonly referred to as GERD (gastroesophageal reflux disorder). Although the illness may result from a wide variety of causes, it is ultimately the failure of the cardiac sphincter located above the stomach that enables a reflux event to occur. A surgical method developed to reduce reflux episodes involves forming tissue folds in the walls of the stomach to reduce the cross-sectional area of the gastroesophageal juncture to mimic the function of the cardiac sphincter. To perform these types of procedures, sewing devices used to suture the stomach wall into folds are used. The procedure typically involves a fiber optic endoscope introduced into the lower esophageal area. A sewing instrument is advanced down the working channel of the endoscope that has an aspiration port for generating negative pressure to suction stomach wall tissue into the sewing instrument where one or more sutures are implanted to hold the suctioned tissue in a folded condition known as application.
Sewing devices for this procedure are described in, for example, GB-A-2165559 and U.S. Pat. No. 5,080,663. According to these references, a sewing device is used for passing a thread through a tissue fold. The sewing device comprises a hollow needle movable between a first pre-tissue penetration position and a second position in which it passes through the tissue, with a thread carrier adapted to be attached to the thread and being receivable within the hollow needle.
Preferably, the sewing device comprises a body that defines a cavity within which the substrate portion can be held, for example, by means of suction. The hollow needle is mounted for movement in the body between the first and second positions. In some versions of the procedure, a suture is inserted into the tissue with a needle, the two ends of which are fed back out of the patient. Typically, a physician fashions a series of half hitches to secure the suture to the subject tissue.
In other embodiments of the procedure, a tag attached to a distal end of the suture and contained within a lumen of the needle is inserted into and past the tissue. With the needle in an advanced position, i.e., with the needle distal tip extending distally beyond the pierced tissue, a pusher forces the tag out of the needle. After retraction of the needle from the tissue, the suture is retracted so that the tag contacts the tissue. The tag functions as an anchor that enables the suture to be secured to the tissue from the proximal end and also disperses the force applied to the tissue by the suture to prevent tearing of the tissue. Such a device and procedure is described in U.S. Pat. No. 5,080,663 to Mills et al., the contents of which are incorporated herein by reference.
One of the significant problems associated with these procedures is the time and number of intubations needed to perform the various procedures endoscopically. Due to a number of concerns, a patient is typically anesthetized for no more than approximately 40 minutes. In this period of time, procedures such as the GERD procedure must be performed to completion. In the GERD procedure, several intubations are performed to create several plications. As many as nine intubations are required to create just one plication. This is the case when half hitches are used to secure the suture. Each half hitch requires the hitch to be made outside the endoscope and then advanced down the endoscope with a pusher. Typically, six half hitches are used per suture thus six intubations are needed to secure the half hitches. The time needed for each intubation substantially reduces the working time to complete a GERD procedure.
One approach to solving this problem is disclosed in U.S. Pat. No. 5,584,861 to Swain. The Swain patent discloses a suture clip and suture clip delivery device that is used in place of half hitch knots. The disclosed suture clip is a cylinder with a plug that can be releasably secured in the cylinder. The disclosed suture clip delivery device includes a tube, the distal end of which has a recess for receiving the suture clip. An axially movable stirrup is provided at the distal end that has the capacity to be moved from a first position that secures the suture clip to the tube and a second position that allows for the suture clip to be removed from the recess.
An aperture is provided in the cylinder to receive the suture. The cylinder is advanced over the suture that exits from a proximal end of the cylinder and enters the tube. An aperture in a sidewall of the tube provides egress for the suture. The plug is then advanced down the tube and into the cylinder. The interfacing walls of the cylinder and plug capture the suture. A pusher is used to force the plug into the cylinder while the stirrup maintains the suture clip in the recess. Following plug insertion, the stirrup, which is offset from the center axis of the tube, is advanced distally from the distal end of the tube to release the suture clip from the tube.
Although the Swain device solves the problem of multiple half hitches, the overall design of the device has certain drawbacks. First, to successfully join the cylinder to the plug to form the suture clip, the stirrup must be physically maintained in a retracted position while an opposing force is applied with a pusher to the plug. Second, the presence of the stirrup inevitably prevents the tube and therefore, the suture clip from being placed tight against the sutured tissue. This opens the possibility for slack to develop between the clip and the tissue, which can potentially lead to a relaxation of the desired tissue fold.
Suture anchors or clips and the means to deliver and secure them are quite common in the medical industry as they play a significant role in simplifying the tedious task of securing tissue previously accomplished by tying knots on sutures. Quite common are metallic twist tie, staples and various forms of plastic or metallic permanent or temporary mechanical means to prevent the suture from slipping through the tissue. As a result of their function, the clips are typically designed to be large to overcome the stresses expected of them. Disclosed are several single and multi-component suture clips as well as a variety of relatively simple compact suture clip delivery devices that can be inserted into a natural body orifice or through the working channel of an endoscope to cinch a suture clip into the desired position in close proximity to or against the application.
It is to be appreciated that the suture clips and suture clip delivery devices disclosed herein have a potentially wide range of applications including, but not limited to, the attachment of devices, e.g., pH monitor to the gastrointestinal wall, the closure of perforations or ulcers and the creation of anastomoses. Another useful application involves the use of radiopaque clips as fluoroscopic markers.
It is an object of the invention to provide a variety of suture clip designs that effectively disburse the forces applied to sutured tissue to prevent tearing. It is a further object of the invention to provide a suture clip delivery device that eliminates the need to manually apply opposing forces to construct a suture clip. Another object of the invention is to provide a suture clip delivery device that enables the user to place the clip tight against the sutured tissue to eliminate or at least minimize any slack development in the suture. A further object is to provide a suture-severing device that severs suture ends proximal to the suture clip. A still further object is to reduce the number of steps needed to assemble and cinch a suture clip and sever the excess suture material. These and other objects of the invention will become apparent from a reading of the following sections.